U.S. patent number 4,881,268 [Application Number 07/056,716] was granted by the patent office on 1989-11-14 for paper money discriminator.
This patent grant is currently assigned to Laurel Bank Machines Co., Ltd.. Invention is credited to Kiyoshi Fujii, Moriatsu Kawakami, Kazuya Kohzu, Shinya Uchida.
United States Patent |
4,881,268 |
Uchida , et al. |
November 14, 1989 |
Paper money discriminator
Abstract
A paper money discriminator for identifying the type of a bank
note by detecting colors thereof from reflected or transmitted
light obtained by irradiating the bank note. The paper money
discriminator is provided with optical fiber bundles disposed so as
to respectively face a light source and color detecting sensors,
and color filters disposed in positions adjacent to the color
detecting sensors. The top ends of the optical fiber bundles face
an inspection point on the bank note. The paper money discriminator
is provided with identifying systems each of which is composed of a
detecting unit, a calculating unit and a money type identifying
unit and is adapted for detecting reflected or transmitted light in
the form of two separated color components issuing from a type of
bank note, obtaining the ratio of these components, and comparing a
signal representing a calculated pattern with the reference pattern
signals, thereby identifying the money type. The discriminator also
has a money type determining unit which determines the type of bank
note when all of the money types respectively identified by the
identifying systems coincide with each other. In this
discriminator, at least one of the detecting units in the
identifying systems is positioned such as to be capable of
detecting a watermark portion of the bank note.
Inventors: |
Uchida; Shinya (Kanagawa,
JP), Kohzu; Kazuya (Nagano, JP), Fujii;
Kiyoshi (Tokyo, JP), Kawakami; Moriatsu
(Kanagawa, JP) |
Assignee: |
Laurel Bank Machines Co., Ltd.
(Tokyo, JP)
|
Family
ID: |
26433693 |
Appl.
No.: |
07/056,716 |
Filed: |
June 2, 1987 |
Foreign Application Priority Data
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Jun 17, 1986 [JP] |
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61-140879 |
Jun 17, 1986 [JP] |
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61-92225[U] |
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Current U.S.
Class: |
382/135; 209/534;
250/556; 356/71; 382/162; 382/165 |
Current CPC
Class: |
G07D
7/0034 (20170501); G06K 9/2018 (20130101) |
Current International
Class: |
G06K
9/20 (20060101); G07D 7/00 (20060101); G07D
7/12 (20060101); G06K 009/00 () |
Field of
Search: |
;382/7,34,65-67 ;209/534
;194/206,207 ;356/71 ;235/379,454,465 ;340/825.34,825.35 ;358/75
;250/226,227,556 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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47-39435 |
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Oct 1972 |
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JP |
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51-6597 |
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Jan 1976 |
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JP |
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51-84695 |
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Jul 1976 |
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JP |
|
Primary Examiner: Moore; David K.
Assistant Examiner: Couso; Jose L.
Attorney, Agent or Firm: Fleit, Jacobson, Cohn, Price,
Holman & Stern
Claims
What is claimed is:
1. A bank note discriminator comprising:
light projecting means for projecting light onto a bank note being
transported, said light projecting means including a light source
and optical fiber bundles for transmitting light from said light
source to the surface of the bank note;
a plurality of detecting means for detecting reflected or
transmitted light which issues from a bank note of a certain type
in response to the projection of light thereon, said plurality of
detecting means being arranged in the widthwise direction of the
bank note being transported, each of said plurality of detecting
means including optical fiber bundles for transmitting reflected or
transmitted light;
two color filter means provided in said optical fiber bundles with
respect to each of said plurality of detecting means and
selectively transmitting two color components different from each
other;
a plurality of calculating means provided with respect to said
plurality of detecting means, each calculating means being
connected to said optical fiber bundles of one of said plurality of
detecting means for producing, in accordance with a time series,
the ratio of two color components supplied from said one of said
plurality of detecting means;
a plurality of money type identifying means provided with respect
to said plurality of calculating means, each money type identifying
means successively comparing a pattern signal calculated in a time
series by corresponding one of said calculating means from said two
color components with reference patterns previously formed and
stored in a time series with respect to different money types, and
each money type identifying means identifying a money type when
judging that the sum of the difference between the pattern signal
and one of said reference patterns falls within a predetermined
range;
a money type determining means which determines a type of the
transported bank note as identifies by said plurality of money type
identifying means when all of the types of money respectively
identified by said money type identifying means coincide with each
other; and
at least one of said plurality of detecting means which are
arranged in the widthwise direction of the bank note being
transported is positioned such as to be capable of detecting a
watermark portion of the bank note being transported.
2. A paper money discriminator in accordance with claim 1, wherein
said optical sensor means includes at least two optical sensors for
detecting different color components of reflected or transmitted
light and said color filter means includes at least two color
filters, each being disposed in a position adjacent to one of said
optical sensors and capable of selectively transmitting a color
component detectable by the optical sensor which is positioned
adjacent thereto.
3. A bank note discriminator in accordance with claim 2, wherein
said two color filter means are provided at the end of said optical
fiber bundles adjacent to said plurality of calculating means.
Description
BACKGROUND OF THE INVENTION
This invention relates to a paper money discriminator for
identifying the type of a bank note by detecting colors thereof
from reflected or transmitted light obtained by irradiating the
bank note.
Generally, a paper money discriminator identifies printed patterns
and the like formed on a bank note by detecting colors thereof from
reflected or transmitted light obtained by irradiating the bank
note, thereby identifying the type of the bank note or judging
whether the bank note is genuine or counterfeit.
Japanese Patent Publication No. 39435/1972 and Japanese Patent
Public Disclosure No. 84695/1976 disclose a type of paper money
discriminator which has a plurality of light sources capable of
irradiating the surface of a bank note from positions thereabove,
and a plurality of color detecting sensors for receiving, through
color filters, reflected or transmitted light traveling by way of
the bank note, the plurality of color detecting sensors being
disposed close to the bank note.
However, in this type of paper money discriminator, the spaces in
which the light sources and the color detecting sensors are
disposed are comparatively large, and, if the area of irradiation
and/or the number of color detecting sensors are increased, these
light sources and color detecting sensors are concentrated in a
limited inspection space, and the disposition of the light sources
and the sensors is respectively restricted. For this reason, the
construction of this type of discriminator tends to be
complicated.
A type of bank note discriminator such as the one disclosed in
Japanese Patent Public Disclosure No. 6597/1976 has previously been
known in which a type, of bank note is identified on the basis of a
brightness pattern detected from reflected or transmitted light
obtained by irradiating the bank note.
The above-mentioned Japanese Patent Public Disclosure No.
84695/1976 discloses an example of another type of bank note
discriminator in which reflected or transmitted light obtained by
irradiating a bank note is detected after being separated into
lights of two different wavelengths (red light and infrared light)
and the bank note is judged to be genuine or counterfeit on the
basis of the ratio of outputs from detected light or the difference
between the same.
The identification of the type of bank note and/or the
discrimination of a real one from a counterfeit is carried out by
combining the outside dimensions or magnetic patterns with the
above types of optical pattern or color discrimination.
The manner of discrimination in the first of the above-described
conventional systems is based on a so-called method of using
monochrome densities, and thus it cannot even recognize the
difference between a bank note and a counterfeit note (monochromic
copy).
The latter is capable of discriminating a bank note from a
color-copy counterfeit or a color-printed counterfeit but incapable
of identifying the type of bank note. An additional means of
identification is therefore required.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a paper money
discriminator which is free from the above-described problems and
which has a simple construction.
It is another object of the present invention to provide a bank
note discriminator which is capable of identifying a type of bank
note by detecting a color pattern and is also capable of
discriminating color-copy counterfeit notes or color-printed
counterfeit notes.
In one aspect, the present invention provides a paper money
discriminator for identifying the type of a bank note by detecting
colors thereof from reflected or transmitted light obtained by
irradiating the bank note, in which optical fiber bundles are
disposed so as to respectively face a light source and color
detecting sensors, the top ends of the optical fiber bundles facing
an inspection point at which the bank note is supported, and in
which color filters are disposed in positions adjacent to the color
detecting sensors.
In this paper money discriminator, the provision of optical fiber
bundles capable of transmitting light enables the light source and
the color detecting sensors to be placed in positions remote from
the inspection region, thereby reducing the restriction on the
disposition of each of the light source and the color detecting
sensors. Also an optical fiber bundle composed of the optical fiber
bundles has a comparatively small diameter and a simple structure.
For these reasons, the structure near the inspection region can be
simplified.
In another aspect, the present invention provides a bank note
discriminator having: detecting units for detecting two different
color components separated from reflected or transmitted light
which issues from a traveling bank note of a certain type, the
detecting units being disposed at a plurality of positions arranged
in the widthwise direction of the bank note being transported;
calculating units provided with respect to the plurality of
detecting units, each calculating unit being adapted for obtaining,
in accordance with a time series, the ratio of two color components
supplied from corresponding one of the detecting units; money type
identifying units provided with respect to the plurality of
calculating units, each money type identifying unit successively
comparing a pattern signal calculated in a time series by
corresponding one of the calculating units from the two color
components with reference patterns previously formed and stored in
a time series with respect to different money types, and each money
type identifying unit identifying a money type when judging that
the sum of the difference between the pattern signal and one of the
reference patterns falls within a predetermined range; and a money
type determining unit which determines the type of traveling bank
note as identified by the plurality of money type identifying units
when all of the money types respectively identified by the money
type identifying units coincide with each other; wherein at least
one of the detecting units which are disposed at the plurality o
positions arranged in the widthwise direction of the traveling bank
note is positioned such as to be capable of detecting a watermark
portion of the traveling bank note.
In this arrangement, each identifying system composed of the
detecting unit, the calculating unit and the money type identifying
unit detects reflected or transmitted light in the form of two
separated color components, obtains the ratio of these components,
and compares a signal representing a calculated pattern with the
reference pattern signals, thereby identifying a bank note or
judging the same to be counterfeit.
At least one of the identifying systems is capable of detecting a
watermark portion of the bank note. Since the difference between
the quantity of paper with respect to the real bank note and a
color-copy counterfeit or a color-printed counterfeit is more
discriminative at the watermark portion, only real bank notes are
positively identified.
The type of bank note is determined only when all the money types
identified by the identifying systems coincide with each other.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an illustration of a paper money discriminator which is
an embodiment of the present invention;
FIG. 2 is a cross-sectional view of a support block and other
related members of the discriminator shown in FIG. 1;
FIG. 3 is a perspective view of the top end of a light receiving
optical fiber cable;
FIG. 4 is an illustration of another embodiment of the present
invention a part of which is omitted.
FIG. 5 is a block diagram of the entire constitution of the
embodiment;
FIG. 6 is a diagram of the relationship between bank notes and the
positions of detecting units;
FIG. 7 is an illustration of an example of a detecting unit of a
reflected light detection type; and
FIG. 8 is a graph of the difference between output signals in
relation to wavelengths obtained at watermark portions of a real
bank note and a counterfeit note.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
A paper money discriminator typical of embodiments of the present
invention will be described below with reference to the
accompanying drawings.
FIGS. 1 to 3 show a paper money discriminator embodying the present
invention which is provided with a paper money transportation path
1 along which a bank note S is transported in the direction
indicated by the arrow in FIG. 1 with its surface facing the path.
A guide plate 2 which prevents the bank note S from floating is
disposed midway on the paper money transportation path 1. A light
projecting optical fiber cable 5 and a light receiving optical
fiber cable 6 each of which is composed of a bundle of a plurality
of optical fiber bundles 4 are inserted into and attached to a
support block 3 which is fixed to the upper surface of the guide
plate 2. The top ends of the optical fiber cables 5 and 6 are held
such as to face a certain position on the upper surface of the
paper money transportation path 1 through an aperture 7 formed in
the support block 3, as shown in FIG. 2. In this embodiment, as
shown in FIG. 3, the light receiving fiber cable 6 has three
optical fiber bundles 4, and color filters 8A, 8B and 8C which are
separately provided with respect to primary colors and which permit
only light of specific frequencies to pass therethrough are
disposed at the top ends of the optical fiber bundles 4. A light
source 9 is disposed near the root end of the light projecting
optical fiber cable 5 such as to project light to the end surface
thereof. Color detecting sensors 10A, 10B and 10C are disposed near
the root end of the light receiving optical fiber cable 6 such as
to respectively face the end surfaces of the optical fiber bundles
4, and a discrimination circuit 11 is connected to the color
detecting sensors 10A, 10B and 10C.
The paper money discriminator thus constituted transmits light from
the light source 9 by way of the light projecting optical fiber
cable 5, irradiates the surface of the bank note S on the paper
money transportation path 1 with light emitted from end surfaces of
the optical fiber bundles 4 of this fiber cable 5, receives
reflected light therefrom by the end surfaces of the optical fiber
bundles 4 of the light receiving optical fiber cable 6 through the
color filters 8A, 8B and 8C, transmits this light to the color
detecting sensors 10A, 10B and 10C, and carries out discrimination
in the discrimination circuit 11. In this arrangement, the light
source 9 and the color detecting sensors 10A, 10B and 10C are
remote from the paper money transportation path 1, and they may be
disposed, for example, in a side portion of the body of a bank note
depositing machine in which this paper money discriminator is
incorporated, thereby facilitating maintenance, overhauling and so
forth. In addition, the diameter of each of the optical fiber
cables 5 and 6 disposed near the paper money transportation path 1
is small (e.g., not more than 5 mm.phi.), so that the structure
around this portion can be simplified.
FIG. 4 shows another embodiment of the present invention in which a
plurality of light projecting optical fiber bundles 4a are disposed
such as to encircle light receiving fiber bundles 4b, thereby
constituting an optical fiber cable 12 and in which the light
projecting optical fiber bundles 4a and the light receiving optical
fiber bundles 4b are ramified from the optical fiber cable 12 and
are positioned such as to respectively face the light source 9 and
the color detecting sensors 10A, 10B and 10C, thereby effecting
irradiation and reception of light through one optical cable.
In the paper money discriminator in accordance with the present
invention, transmitted light may be used to effect discrimination,
and the number of color filters and the kinds of color thereof are
not limited as described above with respect to the first
embodiment. Also the color filters may be placed in any positions
other than those in front of the top end surfaces of the optical
fiber bundles so long as the filters are disposed in the optical
paths leading to the color detecting sensors. The color filters may
be of an optical type or an electric type.
As described above, the paper money discriminator in accordance
with the present invention has the following advantages.
(i) Since light is transmitted by way of the optical fiber cables,
the light source and the color detecting sensors can be placed in
positions remote from the inspection region, thereby reducing the
restriction on the disposition of each of the light source and the
color detecting sensors. Also the optical fiber cable itself has a
comparatively small diameter and a simple structure. For these
reasons, the structure near the inspection region can be
simplified.
(ii) Since the optical fiber bundles can be freely bent, they are
easy to deal with, and it is possible to arrange a plurality of
optical fiber bundles in such a manner that different portions of a
bank note can be irradiated with light issuing from only one light
source. It is also possible to effect discrimination with high
accuracy by receiving reflected or transmitted light after
subdividing the same by means of a plurality of optical fiber
bundles. The applicability of the discriminator is therefore
improved.
The second embodiment according to the present invention which
utilizes the construction of the above-mentioned paper money
discriminator will now be described with reference to FIGS. 5 to
8.
FIG. 5 shows a block diagram of the entire paper money
discriminator which represent a preferred embodiment of the present
invention.
The discriminator in accordance with the present invention has
detecting units 101A to 101C each of which separates reflected or
transmitted light issuing from traveling bank notes S into two
color components such as red (wavelength: 610 nm) and blue
(wavelength: 450 nm) and thereafter outputs detection signals R and
B.
As is clear from FIG. 6 which illustrates the relationship between
the traveling bank notes S and the positions of the detecting units
101A to 101C, the detecting units 101A to 101C are disposed at
positions in which they can detect a plurality of portions of the
bank notes S spaced apart in the widthwise direction thereof while
the banknotes S are being transported in the direction indicated by
the arrow in FIG. 6. At least one of the plurality of detecting
units 101A to 101C is disposed at a position in which it can detect
a watermark portion S' of one of the bank notes S which is being
transported.
As shown in FIG. 6, the bank notes S are exemplified by a
ten-thousand-yen note S1, a five-thousand-yen note S2 and a
thousand-yen note S3.
FIG. 7 shows an example of any one of the detecting units 101A to
101C which is of a reflected light detection type.
In this example, optical fibers are utilized in order to facilitate
the mounting of detecting elements and the like on a bank note
carrying unit. A support block 112 is attached to one of guide
plates 111 which guide the bank notes S which are being
transported. A light projecting fiber cable 113 and light receiving
fiber cable 114 are inserted into and supported by the support
block 112.
A light projecting lamp 115 (e.g., a halogen lamp) is provided at
the end surface of the root portion of the light projecting fiber
cable 113.
The light receiving fiber cable 114 is composed of two optical
fiber bundles 114a and 114b, and light receiving elements 116a and
116b are disposed such as to face the surfaces of the outgoing ends
of the optical fiber bundles 114a and 114b through the medium of
optical filters 115R and 115B (color filters) which permit only
light of above-described particular wavelengths (R=610 nm, B=450
nm) to pass therethrough.
The optical filters 115R and 115B may be disposed such as to face
the surfaces of the light receiving ends of the two groups of
optical fiber bundles 114a and 114b disposed in the support block
112.
To evade errors in discrimination due to fluctuations in the light
intensity level of received light caused by variation of ambient
temperature in the process of comparison and discrimination carried
out by using signals detected by the light receiving elements 116a
and 116b, a compensating plate 117 (e.g., a monochromic plate such
as a white plate) for detecting the light intensity level when
discrimination is not effected may be disposed on guide plates 111
which face the support block 112.
The compensating plate 117 is only applicable to discriminators of
the same type as the reflected light detection type in accordance
with this embodiment. A discriminator of the transmitted light
detection type (not shown) may be arranged in such a manner that
projected light can be directly received so as to effect
compensation by detecting the light intensity level when
discrimination is not effected.
Referring back to FIG. 5, the discriminator in accordance with the
present invention is also provided with calculating units 102A to
102C each of which is adapted for obtaining, in accordance with a
time series, the ratio X of the detected signals R and B (X=R/B)
corresponding to the two color components obtained by each of the
detecting units 101A to 101C, thereby making calculated pattern
signals Xi (Xi=Ri/Bi) in time series.
In order for the calculating units 102A to 102C to obtain the
calculated pattern signal Xi by compensating the detection signals
R and B, each of the calculating units 2A to 2C may detect and
store signals which issue when discrimination of bank notes is not
effected, namely, offset signals Ros and Bos and carry out
calculations:
The discriminator in accordance with the present invention is
further provided with money type discriminating units 3A to 3C each
of which successively compares the calculated pattern signal in a
time series obtained by corresponding one of the calculating units
on the basis of the two color components with reference pattern
signals Ki-n (n=1 to 12: 3 money types.times.4 directions=12
patterns) in time series previously stored with respect to
different money types and each of which identifies a money type
when judging that the sum Y of the difference between the pattern
signal and one of the reference patterns falls within a
predetermined range.
That is, a calculation: Y=.SIGMA.(Xi-Ki-n) is carried out, thereby
selecting one of the reference pattern signals Ki-n which satisfies
a condition:
As is clear from the above description, it is possible to
ascertain, as well as the money type, the direction of each bank
note in which the top or the bottom of the note faces or in which
the normal or the reverse surface of the note faces. Each of the
money type identifying units 3A to 3C incorporates a memory (not
shown) for storing the above reference pattern signals Ki-n, but
otherwise the memory may be provided as a separated part.
The discriminator in accordance with the present invention is
further provided with a money type determining unit 104 which
determines the type of traveling bank note S as identified by the
money type identifying unit 103A to 103C when all of the money
types respectively identified by the money type identifying units
3A to 3C coincide with each other.
It goes without saying that the money type determining unit 104
outputs a counterfeit-note signal when one of the money type
identifying units 103A to 103C identifies a different money type or
direction or judges that it is impossible to identify the note (it
is not possible for any counterfeit note to be identified).
The operation of the discriminator in accordance with the present
invention will be described below.
When the bank notes S are transported between the guide plates 111,
reflected or transmitted light issuing from each bank note S is
detected by the detecting units 101A to 101C while being separated
into the two color components R and B, and the ratio X=R/B thereof
is obtained in each of the calculating units 102A to 102C.
The calculated pattern signals Xi which are obtained by the
calculating units 102A to 102C are compared with the reference
pattern signals Ki-n in the money type identifying units 103A to
103C, thereby identifying the money type (and the direction) or
judging that the note is counterfeit.
At least one of the detecting units 101A to 101C is capable of
detecting the watermark portion S' of one of the bank notes S.
Since the difference between the quantity of paper with respect to
the bank note S and a color-copy counterfeit or a color-printed
counterfeit is more discriminative at this watermark portion S',
only the type of real bank notes is positively identified.
That is, as shown in FIG. 8, which shows the difference between
output signals in relation to different wavelengths, the level of
the output signal obtained at the watermark portion S' of one of
the real bank notes S tends to increase as the wavelength
increases. In contrast, in the case of a corresponding imitation
note IS such as a color-copy imitation or a color-printed
imitation, the level of the output signal tends to be constant at
different wavelengths.
Accordingly, in the case of a color-copy imitation note or a
color-printed imitation note, the calculated pattern signal Xi
obtained at the watermark portion S' of this note largely differs
from the reference pattern signals Ki-n with respect to one of the
identifying systems (detecting units 101A to 101C, the calculating
units 102A to 102C and the money type identifying units 103A to
103C) which detects the watermark portion S' of corresponding one
of the real bank notes S. The imitation note is thereby judged to
be non-identifiable (counterfeit).
The money type determining unit 104 outputs a money-type signal
(also capable of outputting a signal which represents the
direction) only when all of the money types identified by the money
type identifying units 103A to 103C coincide with each other. If
one of the money type identifying units 103A to 103C identifies a
different money type or direction or judges that the note is
non-identifiable, the money type determining unit 104 outputs a
counterfeit-note signal.
According to the present invention, as described above, reflected
or transmitted light is detected after being separated into two
color components, the ratio of these components is obtained, and a
signal representing a calculated pattern is compared with the
reference pattern signals, thereby identifying a bank note or
judging the same to be counterfeit. At least one of the identifying
systems is arranged so that it can detect the watermark portion of
a type of bank note and detect the difference between the quantity
of paper at the watermark portion with respect to the real bank
note and a color-copy counterfeit or a color-printed counterfeit,
thereby identifying only the real bank note. The type of bank note
is determined only when all the money types identified by the
identifying systems coincide with each other. Therefore, it is
possible for the discriminator in accordance with the present
invention to discriminate any color-copy imitation note or
color-printed imitation note as well as ascertain the type of the
bank note by detecting color patterns specific to this bank
note.
* * * * *